Backout device for drilling rigs



W. L. CHILDS BACKOUT DEVICE FOR DRILLING RIGS Filed Sept 10, 1921 a. 9 w III-I: in:

Mil-MAD JNVENTOR.

A TT ORNE Y.

Patented Apr. 3, 1923.

UNITED STATES PATENT OFFICE.

WILLIAM L. CHILDS, OF HOUSTON, TEXAS, ASSIGNOR TO HUGHES TOOL COMPANY, OF HOUSTON, TEXAS, A CORPORATION OF TEXAS.

BACKGUT DEVICE FOR DRILLING RIGS;

Application filed September 10, 1921.

To all whom it may concern Be it known that I, IVILLIAM L. CHILns, a citizen of the United States, residing at Houston, Harris County, Texas, have invented a certain new and useful Improvement in Backout Devices for Drilling Rigs, of which the following is a full, clear, and exact description, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to a backout device to be used on rotaries in well drilling. The device is to be employed in combination with pipe tongs in unscrewing joints of pipe.

' In removing a string of pipe from the well'during the operation of well drilling, it is customary to unscrew the joints of pipe by use of the rotary and, as the joints are being uncoupled, to hold one portYon of the joint to be uncoupled with a pair of breakout tongs and to secure said tongs against movement by contact of the handle thereof with a breakout pin on the derrick platform.

The other portion of the joint is gripped by means of a second or backout wrench. This wrench is rotatedabout the pipe by contact with a backout pin secured in an erect position on the rotary table. The pin contacts with the handle of the wrench and the rotation of the table swings the wrench and the pipe in the proper direction to unscrew the threads at the joint. It has been found in ordinary practice that when the backout wrench has been thus gripped firmly upon the pipe, and the backout pin is held rigidly against the handle of the wrench, the

wrench cannot easily be released'from' this locked position. It is usually necessary to jar the wrench loose by means of hammers.

It is an object of my invention to provide a backout pin which will serve to adjustably support the wrench in proper position and also to provide means for releasing the handle of the wrench when the joint has been unscrewed.

Another object is to provide a backout pin, of the character described, which will be capable of vertical adjustment so as to grip the wrench supported thereon to the pipe at various heights above the rotary, and at the Sametime be capable of releasing the wrench in the manner described.

These and other objects and advantages Serial No. 499,643.

will be more fully set forth in the specification which follows.

Referring to the drawing herewith wherein the preferred embodiment of my invention has been shown, Fig. 1 is a top plan view of a rotary table and pipe showing my improvement employed in connection with the handle of a wrench, said pipe being in transverse section. Fig. 2 is a side elevation of the device. Like numerals of reference are employed in both views in designating like parts.

In the drawing I have shown, more or less diagrammatically, an ordinary type of rotary table used in connection with the rotary system of drilling. This table 3 is mounted upon a lower base 4 supported upon the beams 5. The table 3 is provided at its outer, lower edge with gear teeth which are adapted to mesh with a bevel gear 6 on the power shaft 7. By this means the table 3 is rotated upon the base 4; Centrally of the table is a circular opening through which the pipe 8 may project. On either side of this opening in the rotary table I may provide openings: 9. in which may be removably received my improved backout post 10. At one side of the rotary table and connected with the rotary base or with the derrick platform, I may provide an upstanding breakout pin 11 of any common construction.

The back'out post 10 comprises an upright pin having rotatably and vertically slidable thereon, a bracket 12. At the upper end of the pin is a transverse locking pin 13 held against removal by cotter pins or other similar devices. This locking pin limits the upward movement of the bracket 12. Between the bracket and the rotary table 3, I provide a spiral spring 14. p This spring bears at its lower end upon the rotary table and at its upper end against the bracket with suflicient force to just support the bracket at its upper limit of movement. This allows the bracket to be easily depressed when it is necessary to adjust the same downwardly in use. The bracket 12 is extended horizontally to form a support 15 which is slotted centrally at 16 to provide a space to receive the handle 17 of a pipe wrench 18. The slot 16 is open at its outer end, except for a stop pin 19 which closes the said slot and also projects above the bracket to provide a stop, the purpose of which will later appear.

At the inner end of the slot and centrally thereof is a pivot pin 20 upon which is mounted a cam-shaped lever 21. This lever is rigid with the pivot pin and rotates therewith. The upper end of the pin 20 projects above the bracket and has thereon a crank handle 22, by means of which the lever may be swung toward or away from the wrench handle.

The wrench 18 shown in the drawing is secured firmly upon the pipe 8 by swinging the handle 17 in a clockwise direction, as shown in that figure. Therefore, when the wrench is secured. about thepipe the lever 21 in the slot will be swung away from the wrench handle so as to allow the said wrench handle to move to the right to obtain a grip upon the pipe. The handle of the wrench is then swung in clockwise direction to lock the same firmly on the pipe and, in doing so, the lever 21 is swung into approximately the position shown in Fig. 1. This will bring the handle 22 of the lever against a stop 23 which acts to limit the movement of the lever at the point where the outer end is farthest from the backout post. The handle of the wrench is then somewhat loosely locked between the lever and the stop pin 19. The swinging of the rotary table in the clockwise direction will then swing the backout post and the wrench to the left, and will act to unscrew the joint of pipe. When the unscrewing action has been finished the handle of the wrench is released by swinging the lever handle in a clockwise direction, as shown in the figure, thus swinging the cam away from the handle. This same swinging movement of the handle 22 is continued forcibly until the said handle strikes against the stop pin 19. This gives the handle of the wrench a jar from the opposite side and serves to release it from the pipe after which it may be unlatched and swung away from the pipe by a movement of the bracket upon the post 10. The handle of the wrench is provided with a series of openings 2 therein through which may be passed a pin "25 to limit the longitudinal sliding of the handle in the bracket. This will serve, as will be obvious, to cause the movement of the wrench with the bracket when the bracket is swung away from the pipe.

While I have shown and described my preferred embodiment of the invention, it is obvious that various changes may be made therein without departing from the spirit of my invention. It is also obvious that while I have shown the bracket as supporting a particular form of wrench, my invention is not confined to use with this particular tool, but may be used with any well known type of wrench now in use. The advantages of the device lie particularly in the adj ustability of the bracket .to accommodate the wrench to the joint in various positions of the joint and also in the manner in which the wrench may be firmly gripped to the pipe and quickly released. The swinging of the cam lever away from the locking position is easily accomplished because of the particular cam shape in which the lever is constructed. l 'urther advantage arises from the fact that the same swinging movement which releases the handle also acts to jar the wrench upon the pipe by contact of the handle 22 with the pin 19 so that the wrench will automatically release itself without further action on the part of the operator. The only thing remaining for the operator to do is to swing the jaws free of the pipe and to swing the wrench and the bracket out of their operative position. The further objects and advantages of this device will be obvious to one skilled in the art.

What I claim as new and desire to protect by Letters Patent is:

1. In a device of the character described, a rotary table, a backout post secured therein comprising an upright pin, a bracket slidable vertically thereon, a spring on said pin bearing against said table and said bracket, said bracket having a handle receiving slot therein, a cam shaped lever in said slot, and means to swing said lever laterally. in said slot.

2. In a device of the character described, a rotary table, a backout post secured therein comprising an upright pin, a resiliently supported bracket slidable vertically thereon, said bracket having a handle receiving slot therein, a cam shaped lever in said slot and means to operate said lever.

3. In a device of the character described, a rotary table, a backout post secured therein comprising an upright pin, a resiliently supported bracket slidable verticallythere- .on, said bracket having a handle receiving slot therein, a stop pin at the outer end of said slot projecting above said bracket, a cam shaped lever in said slot, and a handle on said lever adapted to swing said lever and to contact with said stop pin.

at. In a device of the character described, a rotary table, a backout post secured therein comprising an upright pin, a bracket slidable thereon, a lateral slot in said bracket, a wrench handle received in said slot. a cam shaped lever in said slot, adjacent said pin, and means to swing said lever in said slot to lock or release said handle, for the purpose described.

5. In a device of the character described, a rotary table, a backout post secured therein comprising an upright pin, a bracket on said pin, a lateral slot in said bracket, a

wrench handle received in said slot, a stop pin at the outer end of said slot, a lever in said slot adapted to bear against said handle said bracket, a wrench handle slidable on said support, and a locking means on said support.

8. A b ackout post comprising an upright pin, a bracket thereon, a lever on said bracket, a stop means at ,the outer end of said bracket and means to swing said lever toward and from said stop.

In testimony whereof, I hereunto aflix my ignature, this the 6th day of September,

WVILLIAM L. CHILDS. 

